Decide who can play your game, test safely with friends, and get the link into testers' hands.
You've published. Now: who gets in? Permissions decide that, and they're the difference between a safe test with friends and strangers wandering into a half-built world.
Game Settings → Permissions controls the door:
The safe order: build Friends → test → when the game is solid, widen to Public. You can change this any time.
Where do you set whether strangers or only friends can play?
Publishing ≠ discovered. To get testers quickly:
The link is the quickest path from "I built this" to "someone else is playing it." You'll send it a lot while testing.
With permissions set to Friends, the link only works for friends — exactly what you want during a bug hunt.
After publishing, you get testers into the game by copying the link and sending it to friends.
Two terms worth knowing:
For now, Friends permissions + a link is the whole testing loop.
You just published and want two friends to test before strangers. Write the two actions: set permissions to ____, then ____ the link.
-- the safe testing setup
Next: proving your saves actually survive — testing the persistence loop.